Nguyen Van Tam’s 4,000-sq.m grapefruit orchard in Tien Giangprovince’s Cai Lay District has seen its output fall by one-third in thelast harvest season compared to previous seasons because of thedestruction caused by a worm, Citripestis sagittiferella, known locallyas “nam hong”.
Tam says he has lost about 10 million VND (470 USD) from the yield decline.
About 405ha of Tien Giang’s 10,721ha of citrus fruits have beeninfected by the worm. The province’s Department of Agriculture and RuralDevelopment estimates the infection rate at 10-20 percent of the treesin each orchard.
The worm, which penetrates citrusfruits and damages them, has been seen in the Delta provinces of TienGiang, Vinh Long, Ben Tre, Hau Giang and Dong Thap only since 2011,according to the Southern Fruit Research Institute.
The institute has instructed farmers to apply several measures toprotect their grapefruits, including using plastic to cover the fruitand painting the tree trunks white with lime.
Someorchard owners said they have also used nets with lights that attractinsects, but they have not been able to catch the worm.
A new disease has also attacked dragon fruit orchards in Tien Giang, infecting young branches and fruits.
Le Van Minh in Cho Gao District’s Dang Hung Commune said 80 percent ofhis 2,000sq.m orchard were affected by the disease in the last harvestseason.
Nguyen Van Sinh, head of the Tien Giangprovince’s Plant Protection Department, said the disease has beenidentified as the brown spot disease caused by the Neoscytalidiumdimidiatum fungi.
The disease spreads rapidly,especially in the rainy season, and in orchards that maintain poorhygiene and use too much nitrogenous fertiliser and other chemicals tostimulate growth, he said.
The disease, which cannot be treated, has affected both the quality and yield of dragon fruit, he added.
In Long An province, about 967ha of 2,200ha of dragon fruit orchards have been infected by the disease.
The disease was first appeared in the southern central province ofBinh Thuan, the country’s largest dragon fruit producer, in 2009.
Local officials have told farmers that they need to drain water fromdragon fruit orchards, destroy disease-infected branches and fruits anduse fertilisers properly to restrict the disease from spreading.
Besides the new diseases, many fruit orchards, including those growingmilk apple, mango and sapodilla have suffered from a condition in whichthe roots of many trees rotted and the leaves and branches of othersdried up.
Many orchard owners attributed it to fakefertiliser, while others blamed it on inclement weather, stagnant waterand the soil losing nutrition because of the closed dyke systems builtto control floods.
However, local officials sayorchard owners applying techniques to force their trees to produce manyfruits is the major reason for the damage.
TrinhCong Minh, deputy director of Tien Giang province’s Department ofAgriculture and Rural Development, said the price of milk apple andsapodilla was high in previous seasons and many orchard owners hadapplied techniques to make the trees to bear fruits during their offseason.
“This has caused the weakness of fruit trees, causing many trees to die,” he said.
The department is working with the Ministry of Agriculture and RuralDevelopment’s South Plant Protection Department to find measures torescue the trees and orchards, he said.-VNA